Theoretical analysis of thermocapillary flow in cylindrical columns of high prandtl number fluids
Theoretical analysis of thermocapillary flow in cylindrical columns of high prandtl number fluids
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DOI：
10.1115/1.2824346
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发表时间：
1998-08
影响因子：
--
通讯作者：
Y. Kamotani;S. Ostrach
中科院分区：
文献类型：
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作者：
Y. Kamotani;S. Ostrach
从理论上分析了高Prandtl数流体在半区构型中的定常和振荡热毛细管流。通过标度分析确定了基本恒定流的速度尺度和长度尺度。预测的标度律与数值计算结果吻合较好。然后讨论了振荡的物理机制。自由表面的变形通过改变热拐角区附近的温度场改变了流动的主要热毛细驱动力，从而对振荡的开始起到了重要作用。这一现象触发了地表水流经历活跃和缓慢周期的振荡周期。基于这一概念，通过标度分析得到了表面变形参数。形变参数与振荡开始的可用数据很好地关联
Steady and oscillatory thermocapillary flows of high Prandtl number fluids in the half-zone configuration are analyzed theoretically. Scaling analysis is performed to determine the velocity and length scales of the basic steady flow. The predicted scaling laws agree well with the numerically computed results. The physical mechanism of oscillations is then discussed. The deformation of free surface plays an important role for the onset of oscillations in that it alters the main thermocapillary driving force of the flow by changing the temperature field near the hot-corner region. This phenomenon triggers oscillation cycles in which the surface flow undergoes active and slow periods. Based on that concept a surface deformation parameter is derived by scaling analysis. The deformation parameter correlates available data for the onset of oscillations well